Allergic conjunctivitis happens when the direct exposure of the ocular mucosal surfaces to the environment causes an immediate hypersensitivity reaction in which triggering antigens couple to reaginic antibodies (IgE) on the cell surface of mast cells and basophils, leading to the release of histamines that causes capillary dilation and increased permeability and thus conjunctival injection and swelling.
Seasonal allergic conjunctivitis is the most common form of allergic conjunctivitis in temperate climates. It usually occurs and recurs at a certain period of the year (eg summer).
Perennial allergic conjunctivitis manifests and recurs throughout the year with no seasonal predilection. It is most common in tropical climates.

The risk of band keratopathy may be greatly increased in patients with end-stage renal disease (ESRD), and significant risk factors are iridocyclitis and degenerated eye, according to a Taiwan-based cohort study billed as the largest to ever be conducted on the relationship between the two conditions.

Intravitreous administration of the vascular endothelial growth factor (VEGF) inhibitor ranibizumab does not increase the risk of cardiovascular and cerebrovascular events in patients with diabetic macular edema (DME), according to a recent study.

A number of clinical tumour and treatment parameters, most of which are shown to reflect initial tumour size, appear to contribute to the regression of choroidal melanoma after brachytherapy, a recent study has shown.

Eating dark chocolates may have short-term beneficial impacts on vision, according to a recent study, which reports significant improvements in contrast sensitivity and visual acuity following dark vs milk chocolate consumption.